Switching to Faricimab in Patients with Chronic Diabetic Macular Edema Refractory to Previous Anti-VEGF Therapy: Morphological and Functional Outcomes Including Optical Coherence Tomography Angiography Parameters

Background/Objectives: Choriocapillaris flow impairment has been implicated in the pathogenesis of diabetic macular edema (DME), and choroidal vascular insufficiency has been proposed to contribute to poor treatment responses in chronic diseases. However, whether switching to faricimab can significantly improve choroidal and retinal perfusion in eyes with chronic treatment-refractory DME is unclear. Thus, we aimed to evaluate the morphological and functional effects of faricimab in eyes with DME that showed insufficient response to previous anti-vascular endothelial growth factor (VEGF) therapy. Methods: This single-center retrospective study included eyes with pretreated chronic DME that were switched to faricimab and received at least three consecutive injections. The main outcome measures were changes in central macular thickness (CMT), best-corrected visual acuity (BCVA), and optical coherence tomography angiography (OCTA) parameters before and after switching to faricimab. Results: Thirty-eight eyes previously treated with aflibercept-insufficient responders who switched to faricimab were analyzed. The mean CMT decreased significantly from 424.9 ± 164.4 µm before switching to 330.1 ± 75.2 µm after switching to faricimab (p < 0.001). BCVA improved significantly from 0.63 to 0.55 logMAR (p = 0.027). Among the OCTA parameters, choriocapillaris flow deficit and foveal circularity showed significant improvements after switching to faricimab (p = 0.008 and p = 0.048, respectively). Conclusions: Switching to intravitreal faricimab resulted in significant functional and anatomical improvements in eyes with refractory DME in a real-world setting. OCTA-derived microvascular markers also showed favorable changes, which may reflect a vascular-stabilizing effect.